I've written quite a bit on here about it in my build thread and other posts. I wouldn't have traded the experience for anything. It's hard to state the amount of LIFE that exists in the rocks and sand Richard sends. Cup corals, sponges, tunicates, barnacles, clams, feather dusters, porcelain crabs, worms, pods, urchins, coraline algae, etc, etc., most of which are still alive a year later. I spent many hours with a flashlight at night finding new things every time I looked. To me, starting with dry rock would be missing out on all the diversity TBS rock provides.
As for bad, I've had to trap or kill a dozen gorilla crabs and stone crabs. I trapped one pistol shrimp and kept another once I realized they were not that big of a deal and pretty cool critters. The urchins I gave away (Florida purple spine urchins - they kept hatching out of the rockwork - pretty neat to watch grow but once I had SPS, nope). For me trapping the crabs was part of the fun while I waited for my fish to QT. I really didn't have a big issue with any of the "bad" hitchhikers. Check my build thread for more on my experience.
